1977 - Argentina's Mothers of the Plaza de Mayo hold first weekly march to demand return of their disappeared children.

1986 - Soviet government says 197 people were hospitalized following Chernobyl nuclear power plant disaster, that plant's reactor has been shut down and radiation levels are dropping.

1988 - University student hurls three homemade bombs into headquarters of President Roh Tae-Woo's governing party in Seoul, South Korea, and is arrested.

1991 - Cyclone hits Bangladesh, killing at least 125,000 people.

1993 - Tennis star Monica Seles, the world's No. 1 player, is stabbed with a kitchen knife in Hamburg, Germany, by a supporter of her German rival Steffi Graf.

1995 - U.S. President Bill Clinton ends U.S. trade and investment with Iran, accusing the Tehran government of supporting terrorism.

1997 - An airlift starts to ship Rwandan refugees, trapped in Zaire and hunted by rebels, back to Rwanda.

1998 - Argentine police arrest Dinko Sakic, accused of committing atrocities while the commander of a concentration camp in Croatia during World War II.

2004 - Ten countries join the European Union bloc in a historic enlargement that brings them together in a region separated for decades from the West by barbed wire and Soviet ideology. Together, they boost the EU's population to 450 million people.

2008 - DNA tests carried out by a U.S. laboratory prove that remains exhumed last year belong to two children of Czar Nicholas II, Crown Prince Alexei and his sister, Maria, putting to rest questions about what happened to Russia's last royal family.

2009 - Iraq war formally ends for British forces as America's main battlefield ally hands control of oil-rich Basra area to U.S. commanders and prepares to ship out its remaining 4,000 troops.

2011 - Thousands of young people flood an ancient Roman field for an all-night prayer vigil honoring Pope John Paul II on the eve of his beatification, remembering his teachings, travels and his own suffering.

2013 — The leader of Lebanon's Hezbollah militant group says Syrian rebels will not be able to defeat President Bashar Assad's regime militarily, warning that "Syria's friends," including his Iranian-backed military group, are ready to intervene on the government side.

2014 — Ukraine's acting president concedes that his police and security forces are 'helpless to stifle unrest in the country's east where pro-Russian guymen seized more buildings.